discourse/app/assets/stylesheets/desktop/modal.scss

// base styles for every modal popup used in Discourse

.modal-open {
  .dropdown-menu {
     z-index: 2050;
  }
  .popover {
    z-index: 2060;
  }
  .tooltip {
    z-index: 2070;
  }

}

.modal-backdrop {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1040;
  background-color: $secondary_background_color;
  &.fade {
    opacity: 0;
  }
}

.modal-backdrop,
.modal-backdrop.fade.in {
  -webkit-animation: fade .25s;
  animation: fade .25s;
  opacity: 0.8;
  filter: alpha(opacity=80);
}

//fade in

@-webkit-keyframes fade {
    from {opacity: 0}
    to {opacity: .8}
}@keyframes fade {
    from {opacity: 0}
    to {opacity: .8}
}

.modal-outer-container {
  display:table;
  width:100%;
  height:100%;
}
.modal-middle-container {
  display:table-cell;
  vertical-align: middle;
}
.modal-inner-container {
  max-width: 710px;
  margin: 0 auto;
  background-color: $primary_background_color;
  border: 1px solid $primary_border_color;
  border: 1px solid lighten($primary_border_color, 10%);

  box-shadow: 0 3px 7px rgba($primary_shadow_color, .8);
  background-clip: padding-box;
}
.modal {
  position: fixed;
  top: 0;
  width: 100%;
  height: 100%;
  z-index: 1050;
  overflow: auto;
}

// Hardcode to be the same as before for now. I would recommend not using bootbox, or finding a way so the html structure can be the same
.bootbox.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  z-index: 1050;
  overflow: auto;
  width: 610px;
  height: auto;
  margin: -250px 0 0 -305px;
  background-color: $primary_background_color;
  border: 1px solid $primary_border_color;
  border: 1px solid lighten($primary_border_color, 10%);

  box-shadow: 0 3px 7px rgba($primary_shadow_color, .8);
  background-clip: padding-box;

}

.modal.in {
-webkit-animation: modal .25s;
animation: modal .25s;
}

//fade in and animate up

@-webkit-keyframes modal {
    from {opacity: 0}
    to {opacity: 1}
}@keyframes fade {
    from {opacity: 0}
    to {opacity: 1}
}

.modal-body {
  overflow-y: auto;
  max-height: 400px;
  padding: 15px;
}
.modal-form {
  margin-bottom: 0;
}
.modal-footer {
  margin: 0 15px;
  padding: 14px 0 15px;
  border-top: 1px solid $primary_border_color;
}
.modal-footer:before,
.modal-footer:after {
  display: table;
  content: "";
}
.modal-footer:after {
  clear: both;
}
.modal-footer .btn + .btn {
  margin-left: 5px;
  margin-bottom: 0;
}
.modal-footer .btn.right {
  float: right;
}

.modal-footer .btn-group .btn + .btn {
  margin-left: -1px;
}
.modal-header {
  border-bottom: 1px solid $primary_border_color;
  h3 {
    color: $nav-pills-background-color-active;
    font-size: 20px;
    padding: 10px 15px 7px;
  }
  .close {
    float: right;
    font-size: 20px;
    margin: 10px 10px 0;
    text-decoration: none;
    color: $modal-close-button-color;
    cursor: pointer;
    &:hover {
      color: darken($modal-close-button-color,20);
    }
  }
}

.modal {
  .nav {
    padding: 10px 30px;
    background-color: lighten($primary_background_color, 76%);
    li > a {
      font-size: 14px;
    }
    border-bottom: 1px solid $primary_border_color;

  }

  .category-combobox {
    width: 430px;

    .chzn-drop {
      left: -9000px;
      width: 428px;
    }
    .chzn-search input {
      width: 378px;
    }

    .chzn-search-icon {
      margin-top: 8px;
    }
  }

  &.hidden {
    display: none;
  }
  .modal-body {
    textarea {
      width: 99%;
      height: 80px;
    }
    label {
      color: lighten($primary_text_color, 35%);
    }
    p {
      color: $primary_text_color;
      font-size: 13px;
    }
    .archetype-option {
      margin-bottom: 20px;
    }
    .warning {
      color: $warning_text_color !important;
    }
  }
  .password-confirmation {
    display: none;
  }

  section.field {
    margin-bottom: 20px;
  }
}


.flag-modal {
  max-height: 450px;
}

.custom-message-length {
  margin-bottom: 10px;
  margin-left: 20px;
}

.flag-message {
  margin-left: 20px;
  width: 95% !important;
}

.edit-category-modal {
  .modal-body {
    position: relative;
    height: 420px;
    max-height: 420px;
    padding-bottom: 0;
  }
  .secure-category-options {
    margin: 10px 0 0 16px;
    .badge-list {
      margin: 10px 0;
      li {
        margin: 0 4px 8px 0;
        a {
          color: lighten($primary_text_color, 50%);
          cursor: pointer;
        }
        a:hover {
          color: $primary_text_color;
        }
      }
    }
  }
}

.topic-bulk-actions-modal {
  p {
    margin-top: 0;
  }
  &.full .modal-body {
    height: 400px;
    max-height: 400px;
  }
}
.tabbed-modal {
  .modal-body {
    position: relative;
    height: 350px;
  }
}

.modal-tab {
  position: absolute;
}

.split-modal {
  .modal-body {
    position: relative;
    height: 350px;
  }


  #move-selected {
    p {
      margin-top: 0;
    }

    input[type=radio] {
      margin-right: 10px;
    }

    button {
      margin-top: 10px;
      display: block;
      width: 300px;
    }

    form {
      margin-top: 20px;
      #split-topic-name, #choose-topic-title {
        width: 520px;
      }
    }
  }
}

.invite-modal {
  overflow: visible;
  .ember-text-field {
    width: 550px;
  }
}

.reply-where-modal {
  width: 370px;
  margin-left: -185px;
  .modal-footer {
    .btn {
      text-align: left;
      font-size: 18px;
      line-height: 20px;
      width: 310px;
      margin-bottom: 10px;
      display: block;
      margin-left: 0;
      .topic-title {
        font-size: 13px;
        font-weight: normal;
      }
      &.btn-reply-here {
        background: lighten($secondary_background_color, 60%);
        text-shadow: none;
        color: lighten($primary_text_color, 35%);
      }
    }
    .cancel {
      text-decoration: underline;
      float: right;
      margin-right: 5px;
    }
  }
}

.delete-user-modal {
  .modal-footer {
    .btn {
      font-weight: normal;
      text-align: left;
      font-size: 14px;
      line-height: 20px;
      margin-bottom: 10px;
      display: inline-block;
      margin-left: 0;
    }
    .cancel {
      text-decoration: underline;
      display: block;
      margin-right: 5px;
    }
  }
}

.modal-footer .cancel-inline {
  text-decoration: underline;
  margin-left: 10px;
}

.permission-list{
  list-style:none;
  margin: 0 0 30px;
  padding: 0;
  .name {
    margin-right: 20px;
    display: inline-block;
    min-width: 100px;
  }
  .permission {
    margin-left: 20px;
  }
  .fa-times-circle {
    margin-left: 5px;
  }
  li {
    margin-bottom: 10px;
  }
}